Seeds of endospermic legumes accumulate polysaccharides as storage polysaccharides referred to as gums because these polysaccharides produce gels or highly viscous solutions at low concentrations in solvents, and thus, these polysaccharides have a myriad of applications in industry (Whistler et al., Introduction to industrial gums, In Industrial Gums: Polysaccharides and their derivatives, Whistler and BeMiller, eds., Academic Press, San Diego, pp. 1-19, 1993). The main sources of seed-derived industrial gums are guar (Cyamopsis tetragonoloba), locust bean or carob (Ceratonia siliqua), tara (Caesalpinia spinosa), and fenugreek (Trigonella foenum-graecum), which are all native to subtropical areas. Another class of plant gums, xyloglucans, has not received much attention perhaps because of the low yield of the source seeds. Xyloglucan occurs as a storage polysaccahride in the seeds of nasturtium (Tropaeolum majus), tamarind (Tamarindus indica), and balsam (Impatiens balsamina) (Maier et al., Guar, Locust Bean, Tara, and Fenugreek gum, In Industrial Gums: polysaccharides and their derivatives, Whistler and BeMiller eds., Academic Press, Inc., London, pp. 181-226, 1993; Reid et al., Adv. Bot. Res. 11:125-155, 1985).
As they can absorb large volumes of water, gums are used as food additives to provide texture, prevent ice crystal formation, maintain crispness, and retain moisture (Maier et al., Guar, Locust Bean, Tara, and Fenugreek gums. In Industrial Gums: polysaccharides and their derivatives, Whistler and BeMiller, eds., Academic Press, Inc., London, pp. 181-226, 1993; Anderson and Andon, Cereal Foods World 33:844-850, 1988; Ward and Andon, Cereal Foods World 38:748-752, 1993; Bayerlein, Technical applications of galactomannans. In Plant polymeric carbohydrates, Meuser Manne, and Seibel eds., The Royal Society of Chemistry, Cambridge, pp. 191-202, 1993; Whistler and BeMiller, Guar and Locust Bean Gums, American Society of Cereal Chemists, St. Paul, Minn., pp. 171-177, 1997). Other uses of gums are in the following non-food industries: a) textiles, as dying and printing aids; b) petroleum, as drilling agents for oil and gas wells; c) paper, as binders and hardeners; d) mining and minerals, for separation of minerals from crude ores; e) explosives, to thicken explosive slurries and as desiccants; and f) cosmetics, to thicken shampoos and conditioners (Maier et al., Guar, Locust Bean, Tara, and Fenugreek gums. In Industrial Gums: polysaccharides and their derivatives, Whistler and BeMiller, eds., Academic Press, Inc., London, pp. 181-226, 1993; Bayerlein, Technical applications of galactomannans. In Plant polymeric carbohydrates, Meuser Manners, and Seibel eds., The Royal Society of Chemistry, Cambridge, pp. 191-202, 1993; Soni, Indian Forester 110:931-935, 1984; Siharma, Indian Forester 111:149-157, 1985; Prakash, Bucharest: Academia Republicii Socialiste Romania. 18:207-212, 1984; Pszczola, D. E., Food Technology 47:94-6, 1993; Bayerlein et al., Official Gazette Of The United States Patent And TrademarkOffice Patents 1102:424, 1989; Sudhakar et al., Food Hydrocolloids 10:329-334, 1996). A new, rapidly emerging area for gum applications is human health and medicine where they have been reported to be useful as soluble fiber (Cameron-Smith et al., Journal Of Nutrition 127:359-364, 1997), in lowering blood cholesterol and blood pressure (Blake et al., American Journal Of Clinical Nutrition 65:107-113, 1997), as weight-loss facilitators (Brennan et al., Journal Of Cereal Science 24:151-160, 1996), in lowering blood glucose (Fairchild et al., British J. Nutrition 76:63-73, 1996), as aids for slow release of pharmaceutical drugs (Waaler et al., Acta Pharmaceutica Nordica 4:167-170, 1992), in improving microflora of the digestive system (Takahashi et al., Nutrition Research 15:527-536, 1995), and in prolonging the release of sugar during strenuous physical exercise (Maclaren et al., International Journal Of Sports Medicine 15:466-471, 1994). On a scientific technical note, gums have been used as substitutes for polyethylene glycol in phase partition systems for the separation of cell organelles and membranes (Venancio et al., Bioseparation 5:253-258, 1995).
Natural industrial gums are currently prepared from bacteria or the aforementioned plants or trees. Guar and locust bean account for more than 70% of the natural plant gum market (Bayerlein, Technical applications of galactomannans. In Plant polymeric carbohydrates, Meuser Manners, and Seibel eds., The Royal Society of Chemistry, Cambridge, pp. 191-202, 1993). With an annual global demand for guar and locust bean gums of 200 million pounds and 35 million pounds at a price of $0.70 and $16 per pound, respectively, the market size translates into a $700 million which, when combined with other plant gums, exceeds $1 billion (Bayerlein, Technical applications of galactomannans. In Plant polymeric carbohydrates, Meuser Manners, and Seibel eds., The Royal Society of Chemistry, Cambridge, pp. 191-202, 1993; Industrial uses of agricultural materials: situations and outlook, Volume ISU6, D. Decker, ed. United States Department of Agriculture Washington, D.C., p. 54, 1996).
High price has probably been the reason for a slow expansion of the market size for gums. Production of gums at a lower cost should substantially increase the market size, given that a multitude of applications are already in place. Maier et al., Guar, Locust Bean, Tara, and Fenugreek gums. In Industrial Gums: polysaccharides and their derivatives, Whistler and BeMiller, eds., Academic Press, Inc., London, pp. 181-226, 1993). Whistler and BeMiller, Guar and Locust Bean Gums. In Carbohydrate chemistry for food scientists, Whistler and BeMiller, eds. American Society of Cereal Chemists St. Paul, pp. 171-177, 1997).